After all these bug fix and maintenance tasks, I finally sat down to fix the current balance issues for people with large game lists (at the moment it is far too easy).
I've changed the way in which games are sorted, it's now getting the required number of games, then sorting by reverse time played for HP - which makes it significantly more difficult for people with larger lists and slightly harder for people with average lists.
This is a server-side change, so no game update.
Leaderboards probably need a reset due to this, but that will sort itself out when I setup Season 1 (we're currently on Season 0)
Enjoy!